/*
  planner.h - buffers movement commands and manages the acceleration profile plan
  Part of Grbl
  
  The MIT License (MIT)

  GRBL(tm) - Embedded CNC g-code interpreter and motion-controller
  Copyright (c) 2009-2011 Simen Svale Skogsrud
  Copyright (c) 2011-2012 Sungeun K. Jeon
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.
*/

#ifndef planner_h
#define planner_h
                 
// The number of linear motions that can be in the plan at any give time
#ifndef BLOCK_BUFFER_SIZE
  #define BLOCK_BUFFER_SIZE 18
#endif

// This struct is used when buffering the setup for each linear movement "nominal" values are as specified in 
// the source g-code and may never actually be reached if acceleration management is active.
typedef struct {

  // Fields used by the bresenham algorithm for tracing the line
  uint8_t  direction_bits;            // The direction bit set for this block (refers to *_DIRECTION_BIT in config.h)
  uint32_t steps_x, steps_y, steps_z; // Step count along each axis
  int32_t  step_event_count;          // The number of step events required to complete this block

  // Fields used by the motion planner to manage acceleration
  float nominal_speed;               // The nominal speed for this block in mm/min  
  float entry_speed;                 // Entry speed at previous-current block junction in mm/min
  float max_entry_speed;             // Maximum allowable junction entry speed in mm/min
  float millimeters;                 // The total travel of this block in mm
  uint8_t recalculate_flag;           // Planner flag to recalculate trapezoids on entry junction
  uint8_t nominal_length_flag;        // Planner flag for nominal speed always reached

  // Settings for the trapezoid generator
  uint32_t initial_rate;              // The step rate at start of block  
  uint32_t final_rate;                // The step rate at end of block
  int32_t rate_delta;                 // The steps/minute to add or subtract when changing speed (must be positive)
  uint32_t accelerate_until;          // The index of the step event on which to stop acceleration
  uint32_t decelerate_after;          // The index of the step event on which to start decelerating
  uint32_t nominal_rate;              // The nominal step rate for this block in step_events/minute

} block_t;
      
// Initialize the motion plan subsystem      
void plan_init(void);

// Add a new linear movement to the buffer. x, y and z is the signed, absolute target position in 
// millimaters. Feed rate specifies the speed of the motion. If feed rate is inverted, the feed
// rate is taken to mean "frequency" and would complete the operation in 1/feed_rate minutes.
void plan_buffer_line(float x, float y, float z, float feed_rate, uint8_t invert_feed_rate);

// Called when the current block is no longer needed. Discards the block and makes the memory
// availible for new blocks.
void plan_discard_current_block(void);

// Gets the current block. Returns NULL if buffer empty
block_t *plan_get_current_block(void);

// Reset the planner position vector (in steps)
void plan_set_current_position(int32_t x, int32_t y, int32_t z);

// Reinitialize plan with a partially completed block
void plan_cycle_reinitialize(int32_t step_events_remaining);

// Reset buffer
void plan_reset_buffer(void);

// Returns the status of the block ring buffer. True, if buffer is full.
uint8_t plan_check_full_buffer(void);

// Block until all buffered steps are executed
void plan_synchronize(void);

#endif
